<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style type="text/css">
        .father {
            width: 500px;
            height: 400px;
            background: #232322;
            overflow: hidden;
        }
        
        .son {
            width: 200px;
            height: 200px;
            background: #eee;
            margin-top: 30px;
        }
    </style>
</head>

<body>
    <div class="father">
        <div class="son">

        </div>
    </div>
</body>

</html>